INFO: task syz-executor:3143 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:0 pid:3143 tgid:3143 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:6016 [inline]
__schedule+0x134f/0x1ea0 kernel/sched/core.c:7864
__schedule_loop kernel/sched/core.c:7945 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7960
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8017
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
ip_tunnel_init_net+0x30c/0x890 net/ipv4/ip_tunnel.c:1145
ipgre_init_net+0x28/0x30 net/ipv4/ip_gre.c:1070
ops_init+0x1b2/0x5d0 net/core/net_namespace.c:139
setup_net+0x227/0x9b0 net/core/net_namespace.c:356
copy_net_ns+0x512/0xa30 net/core/net_namespace.c:510
create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x502/0x880 kernel/fork.c:3356
__do_sys_unshare kernel/fork.c:3427 [inline]
__se_sys_unshare kernel/fork.c:3425 [inline]
__x64_sys_unshare+0x3c/0x50 kernel/fork.c:3425
x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f227a99da67
RSP: 002b:00007fff80dcaa58 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f227ac15f40 RCX: 00007f227a99da67
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f227ac167b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fff80dcac98 R15: 0000000000000000
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a88889f1fd4bd040639a1a4060abea1bc20e1fef
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xdad/0xf00 kernel/hung_task.c:423
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 359 Comm: kworker/0:3 Not tainted syzkaller #0 a88889f1fd4bd040639a1a4060abea1bc20e1fef
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:ip6_mc_input+0x118/0x6c0 net/ipv6/ip6_input.c:503
Code: 27 65 49 ff 84 24 b8 00 00 00 48 8b 44 24 20 4c 8d 78 70 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 e9 04 00 00 41 8b 07 <65> 49 01 84 24 d8 00 00 00 48 8b 44 24 20 4c 8d 78 58 4c 89 f8 48
RSP: 0018:ffffc900000079e0 EFLAGS: 00000246
RAX: 0000000000000038 RBX: ffff888146c6ab50 RCX: ffff8881113f3900
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff888146c6ab40
RBP: ffffc90000007ab8 R08: 0000000000000000 R09: ffff888146c6ab40
R10: 0000000000000000 R11: ffffffff84f11cd0 R12: 0000607e08e13090
R13: dffffc0000000000 R14: 1ffff11028d8d56a R15: ffff888146c6abb0
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb13aa12060 CR3: 000000010b760000 CR4: 00000000003526b0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
dst_input include/net/dst.h:469 [inline]
ip6_rcv_finish+0x360/0x3e0 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:317 [inline]
ipv6_rcv+0xf1/0x240 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core net/core/dev.c:5776 [inline]
__netif_receive_skb net/core/dev.c:5889 [inline]
process_backlog+0x44b/0xad0 net/core/dev.c:6225
__napi_poll+0xd0/0x610 net/core/dev.c:6876
napi_poll net/core/dev.c:6945 [inline]
net_rx_action+0x5ea/0xd80 net/core/dev.c:7067
handle_softirqs+0x1aa/0x630 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xb8/0x110 kernel/softirq.c:503
__local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
__raw_write_unlock_bh include/linux/rwlock_api_smp.h:281 [inline]
_raw_write_unlock_bh+0x33/0x70 kernel/locking/spinlock.c:366
neigh_periodic_work+0xa73/0xbc0 net/core/neighbour.c:1024
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
net_ratelimit: 108277 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:7a:f5:15:9f:5d:24, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:7a:f5:15:9f:5d:24, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)